An Assessment of the National Institute of Standards and Technology Engineering Laboratory: Fiscal Year 2014 (2015)

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Energy and Environment Division

The Energy and Environment Division (EED) of the EL develops measurement science, predictive models, and performance metrics to improve the energy efficiency of building components and systems, reduce building-related CO₂ emissions, enhance the quality of the indoor environment, and improve the building design and construction process through the integration of information, communications, sensing, and automation technologies.¹

TECHNICAL PROGRAMS

The EED has two major programs that support its goal of sustainable and energy-efficient manufacturing, materials, and infrastructure. The Net-Zero Energy, High-Performance Buildings Program focuses on understanding building systems and advancing the measurement science for their characterization and performance assessment, and the Embedded Intelligence in Buildings Program focuses on the development and application of intelligent information and control technologies to improve building operation.

Net-Zero Energy, High-Performance Buildings Program

The program includes 12 projects distributed among four thrusts—whole building metrics, envelope load reduction, equipment efficiency, and on-site energy generation—all of critical importance for achieving the program objective of developing and deploying advances in measurement science to move the nation toward cost-effective, net-zero energy buildings while maintaining a healthy indoor environment.

Accomplishments

The program has focused on the measurement science necessary for the development of net-zero energy buildings with healthy indoor environments. A unifying piece of the work is the development of an approach to designing and operating net-zero energy single-family houses, as demonstrated in the NZERTF, which has been collecting data on its energy use for a year. The NZERTF will enable detailed simulation of the effects of occupant activities and building dynamics on energy and IEQ. Through a year-long monitoring of performance, the NZERTF has generated previously unavailable data, including data on the effects of outdoor temperature variation on several parameters, including the pollutant emissions from building envelope materials, the impact of these emissions on indoor air quality, the variation of ventilation rate over time, and energy and water consumptions. The facility is also versatile

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¹ National Institute of Standards and Technology, ‒The Engineering Laboratory—summaries of Our Activities, Accomplishments and Recognitions,” Gaithersburg, Md., July 2014.

for evaluating different heating, ventilating, and air-conditioning systems. For example, three different types of geothermal heat pump systems can be readily tested concurrently at the facility.

Another highlight of the program is the development of new metrics and tools to assess the sustainability of buildings, including a novel metric for assessing the different aspects of IEQ. Using the new metrics, the Building Industry Reporting and Design for Sustainability (BIRDS) software has been developed for the assessment of building systems’ energy, economic, and environmental performance.

A third area of accomplishment is the development of reference materials and reference databases in an effort to reduce uncertainties in the testing and evaluation of indoor air contaminant emission sources, insulation materials, HVAC&R equipment with various refrigerants, and energy monitoring systems. Examples include a new reference material for calibrating environmental chambers for emission testing; thermal insulation standard reference materials (SRMs) and the reference database for building insulation; and two standard reference databases for HVAC&R equipment using various refrigerants, Cycle D (SRD49) and REFLEAK (SRD73).

A fourth area of accomplishment is the development of modeling and simulation tools for model-based testing and evaluation that would enable extrapolation of laboratory testing results to field conditions, useful for system optimization. The tools include a model and software tool (EVAP-COND) to optimize the effectiveness of heat exchangers used in a vapor compression system; and an integration of multizone airflow, IAQ, and energy modeling tools via coupling of the CONTAM airflow modeling tool with the TRANSYS (transient system simulation) building system modeling tool and with the Department of Energy’s EnergyPlus software modeling suite.

Research findings from the program have also made significant contributions to the development of industrial, national, and international standards. They include several ASTM standards in the area of photovoltaics, thermal insulation, material emissions, building economics, and green concrete and corresponding ISO standards.

Opportunities and Challenges

There remain several significant challenges and research opportunities for the program. Metrics are essential for evaluating IEQ and energy performance, and sustainability of buildings remains a major challenge in the field. Many design factors such as form and massing, building envelope, and ventilation system interact to affect both IEQ and energy performance of buildings. A single index does not exist for quantifying IEQ. Many aspects need to be considered, including thermal environment, pollution and noise levels, lighting quality, and occupant satisfaction. It is important to develop an accepted means of quantifying the IEQ benefit to allow comparison with the more measurable energy benefit.

A second challenge lies in the development of an approach to organizing the large amount of data to be collected from the various advanced system testbeds, ranging from material to assembly/component to system-level data, each with associated uncertainties. Such vast and valuable data need to be organized effectively and shared efficiently among research and industrial communities.

A third challenge is to develop a more comprehensive framework for modeling and simulating whole building performance, based on the fundamental understanding of the combined heat, air, moisture, and pollutant transport processes in building systems. Building systems are complex, involving multiscales both spatially and temporally. The transport processes are affected by material characteristics, properties of pollutant species, and environmental conditions. With its capabilities in laboratory measurements and modeling, the EED is in the right position to lead a national effort to develop such a framework.

A fourth challenge is to develop methods and procedures for obtaining reliable data in field investigation that would validate the models and measurement methods that are developed based on laboratory studies. Many existing field studies do not have enough rigor to generate reliable data, and such data sets are difficult, if not impossible, to compare with one another. A standard test protocol based on sound measurement science is essential, which presents an opportunity for EED research.

Overall Assessment

The program has focused on the essential technical areas and built unique research facilities and modeling capabilities needed to achieve its objective of advancing measurement science for developing healthy net-zero energy buildings. A combination of experimental and modeling approaches has been applied, enabling the development of test and evaluation methods from materials, assemblies/components, and systems levels. The quality of the research conducted in the program is nationally and internationally recognized, and it is at a very high level. The results of the research have contributed significantly to the advancement of both code reference standards such as ASHRAE/IES 90.1 and ASHRAE 62.1 and 62.2 and the standard for high-performance buildings such as ASHRAE/IES/USGBC 189.1. These standards are being adopted across the country, universally referenced, and used by the building industry, and they have significantly influenced building standards in other countries.

Embedded Intelligence in Buildings Program

The program focuses on improving building operation through the use of advanced information and control technologies. It has six projects in four thrusts: system commissioning, automated fault detection and diagnosis (FDD), intelligent agent-based optimization, and integration with smart grids, all of which are critically important in achieving the program’s objective of developing and deploying advances in measurement science that will improve building operations to achieve energy efficiency, occupant comfort, and safety through the use of intelligent building systems.

Accomplishments

The program has focused on the measurement science necessary for the successful application of information and control technologies to improve the operation of buildings for human health, safety, and performance. A unique smart building automation and control testbed has been developed that is capable of emulating a variety of buildings and climate conditions in support of commissioning and FDD technology development and of providing technical inputs to improve key industrial standards, including the widely adopted building automation and control network (BACnet) and BACnet conformance testing standards. The testbed enables accurate and reliable assessments of a variety of control algorithms, industrial controllers, and communication devices that are compatible with BACnet. More than 780 companies manufacturing building controllers and mechanical equipment have adopted the BACnet protocol for controller communication, and the number of BACnet vendors continues to increase at a fast pace. Market estimates indicate that more than 50 percent of worldwide sales of new building controllers are BACnet.

The division has developed several important and valuable software tools, including an advanced commissioning software tool, HVAC-Cx, that enables the use of data from building energy management systems (BEMS) for FDD as well as for improving the commissioning process; a beta version of the FDD software tool FDD EA (FDD Expert Assistant); an FDD tester/evaluator software for air conditioners and heat pumps; and a fault-free and fault database for wide application by industrial FDD developers.

Comprehensive simulations and analyses have also been conducted to show the energy-saving potential of using the intelligent agent optimization approach. A unique full-scale facility for testing and evaluating intelligent agent algorithms has been designed and is under construction. It will enable collection of reliable reference data sets for the development and evaluation of intelligent controllers (e.g., model-based predictive controllers), FDD algorithms and devices, and intelligent agent-based optimization methods.

Opportunities and Challenges

There remain several significant challenges and research opportunities to fully realizing the program’s objective. It is essential to investigate the applicability of the FDD and intelligent agent optimization algorithms to a wider range of building types. Prototype buildings defined by the EED can be compared with those defined by the DOE’s Pacific Northwest National Laboratory to suggest a set of standard baselines for buildings of different types. Initial testing and evaluation of the algorithms can be conducted for these reference buildings, and then the sensitivity of the FDD and optimization results to the variation of physical parameters of buildings under different climate conditions can be examined. Such an effort would result in standard test and evaluation methods for the FDD and intelligent-agent-based optimization algorithm with quantifiable uncertainty, and this could help in the development of more robust industrial FDD and intelligent controllers for building operation.

The testbeds for communication, FDD, and intelligent controllers provide opportunities to generate a large number of reference data sets that can be used by industry to accelerate the development of intelligent controllers and building systems. A systematic approach needs to be developed to manage such a large set of databases and disseminate them to industries.

Opportunities also exist for developing simplified local controllers that are coordinated by central intelligence residing in server(s). This is possible with advances in the “Internet of things” and cloud computing. This approach could enable “plug and play” controllers and significantly reduce the complexity in control system maintenance at the local level.

The current focus of the program has been at the building level/scale; at the same time, a communication method has been developed for integration with Smart Grid. With more resources, substantially more energy saving and environmental benefit can be obtained by extending the intelligent-agent optimization approach to the neighborhood, city, and regional scales.

Overall Assessment

The Embedded Intelligence in Buildings Program has focused on the essential technical areas. It has built unique research facilities and modeling capabilities needed to achieve its objective of improving building operation through the use of intelligent information technologies for FDD and system optimization. Unique testbeds combining model simulation and hardware emulation of controllers have been established, enabling the development of test and evaluation methods for both conventional and intelligent FDD and controllers. The quality of the research conducted in the program is nationally and internationally recognized, and it is at a very high level. The results of the research have contributed significantly to the advancement of critical national and international standards such as ASHRAE 135 and EN/SIO 16484-5 for BACnet and ASHRAE 135.1 and EN/ISO 16484-6 for BACnet testing, which are widely used by the building control industry.

Overall Assessment

EED is among the world’s best governmental laboratories in its field, conducting research in carefully selected areas of high-performance buildings, complemented by collaboration with universities and other agencies.

The division designed and had constructed several state-of-the art research facilities to enable benchmark data collection, model validation, and development of standard methods of tests. Examples are the NZERTF, the smart building automation and control testbed, the mini breadboard heat pump, and the intelligent agent control laboratory, whose initial construction is under way. EED used the NZERTF to develop and demonstrate an approach to achieve net-zero energy performance in single-family residential houses under Washington, D.C., climate conditions. Year-long data were collected on energy and IAQ

performance; these data will enable validation of simulation models for prediction and extrapolation to other climates. The facility is unique in its capability to simulate the effects of occupants’ behavior and its detailed monitoring of the environmental conditions, indoor and out.

Integrated multizone airflow and IAQ modeling and building energy simulation tools were developed by coupling CONTAM a (multizone indoor air quality and ventilation analysis computer program) with TRANSYS (an energy simulation software package) and by coupling CONTAM with EnergyPlus (a whole building energy simulation program).

EED personnel were the first to propose and demonstrate the capability to optimize refrigerant circuitry in evaporators and condensers using an artificial intelligence-based optimization module named ISHED (Intelligent System for Heat Exchanger Design), which is embedded in EVAP-COND 3.0 software package. The EED also developed comprehensive standard reference refrigerant databases that provide the information needed for refrigerant screening by manufacturers of refrigeration and air conditioning systems; the first reference materials for calibration of environmental chambers for emissions testing; and an Internet interface, BIRDS, which allows users to compare a whole building’s energy, environment, and economic performance across a variety of factors.

Opportunities and challenges for the division include the need for collection of long-term energy and IAQ performance data at the NZERTF; field validation of models and measurement methods that are based on laboratory studies, such as the FDD evaluation and intelligent building agents; and development of metrics for concurrently evaluating IAQ and energy performance.

PORTFOLIO OF SCIENTIFIC EXPERTISE

Accomplishments

The EED’s yearly research portfolio selection and review process is clearly defined and followed; it includes quarterly reviews of programs and continuous milestone tracking. The division has excellent capabilities in its current focus areas. The projects appear to be focused to take advantage of these excellent capabilities. Recruiting is targeted at specific areas of expertise that build on existing expertise or that expand to areas adjacent to existing areas of expertise. New or expanded skills include fault detection and diagnostics, particle imaging, velocimetry measurements, volatile organic compound (VOC) measurements, and photovoltaic spectral response measurement.

There is need for expertise that is not contained within the division, but it is found elsewhere in the EL or through contract and grant programs. A review of funding allocations for the EED showed that significant support was received from other divisions of the EL and other laboratories at NIST. This approach to pulling in expertise on an as-needed basis helps to maintain consistency within division technical expertise. Successful recruitment of competent early-career researchers and good retention of capable staff has led to healthy demographics, with 28 percent of scientific and engineering staff having joined within the past 5 years. The successful recruitment of qualified early-career researchers and good retention of highly capable staff has led to healthy demographics, complemented by the extension of capabilities through appropriate use of grants and contracts. The division exhibits a good mix of modeling and experimental expertise.

Opportunities and Challenges

The division needs to expand its areas of expertise, especially in the areas of combined heat, air, moisture, and pollutant transport. This expansion will be needed because of the increasing need to control moisture and mold in net-zero energy buildings.

Overall Assessment

Overall, the EED exhibits excellent capabilities in the areas of existing expertise, but the scope of its expertise may be too narrow to include critical IAQ areas such as moisture/mold and nanoparticles.

FACILITIES, EQUIPMENT, AND HUMAN RESOURCES

Accomplishments

Consistent with its objective of developing and deploying advances in measurement science within its program areas, the EED has built on team expertise to expand its capabilities to develop data sets and unique facilities capable of best-in-class measurements. In some cases, EED staff were able to leverage one-time funding opportunities—for example using American Recovery and Reinvestment Act funds to aid in the building of the NZERTF.

The new facilities and equipment include the NZERTF, which was designed to improve and develop test methods and performance metrics for energy-efficient and renewable energy technologies and to examine system interactions; the mini breadboard heat pump, designed to measure the cycle performance of new refrigerants; the Solar Cell Spectral Response Measurement Facility, designed to measure the absolute spectral response of solar cells; the 500 mm guarded hot plate, designed to measure the thermal conductivity of insulation materials over a temperature range of 90 K to 900 K ; the Intelligent Agent Control Laboratory, designed to examine advanced intelligent control techniques; the VOC emission microchambers, designed to measure VOC emissions from building materials; and the particle image velocimetry equipment, designed to measure flow distributions of gaseous fluids.

Overall Assessment

The division has accomplished the upgrading and building of new strategically important facilities. The EED has developed several unique and best-in-class equipment and facilities. Communication within the division benefited from constant informal exchanges and an open-door policy along with formal team and group meetings. A challenge for the division is to obtain sufficient manpower and resources to fully utilize its facilities and to process and disseminate data.

DISSEMINATION OF OUTPUTS

Accomplishments

Stakeholders, customers, and collaborators are identified by the division by several means: its leadership in professional organizations; participation in Department of Energy (DOE) and national laboratories planning; participation in standards development activities; participation in professional and technical meetings; initiating and/or participating in roadmapping exercises; and direct interactions with DOE, national laboratories, universities, and industry. Stakeholders include standards organizations—for example, the ASHRAE, the ASTM, the American Society of Mechanical Engineers (ASME), the International Electrotechnical Commission (IEC), and the ISO—trade associations such as the Air Conditioning Contractors of America (ACCA); the Association of Home Appliance Manufacturers (AHAM); the Air-Conditioning, Heating, and Refrigeration Institute (AHRI); and the National Electrical Manufacturers Association (NEMA); and building owners and operators, contractors, and home buyers.

The EED primarily disseminates research findings through publications, support of standards development, and development and distribution of software. Significant accomplishments are evidenced

by the incorporation of the division’s research into and their support of the development of major industry standards.

One example of this is the leadership shown in improved requirements in green building codes, standards, and programs, including performance credit for improved airtightness for ASHRAE/IES 90.1, the performance-based ventilation option included in Standard 62.2; a proposal for the ASHRAE Residential IAQ Design Guide, the air barrier commissioning addendum included in Standard 189.1; the proposal for ASHRAE Standard 189.2P; and Standard 189.1-2014, published for inclusion in the 2015 International Green Construction Code.

Another example is the development of intelligent systems and technology standards. EED staff hold leadership positions in several key national and international standards committees, including ASHRAE/IES/USGBC 189.1, ASHRAE GPC 10, ASHRAE SSPC 135 (BACnet), ASHRAE SPC 201P Facility Smart Grid Information Model (FSGIM), ASHRAE GPC 0.2, 1.2 (Existing Building Cx) SPC 207P (Method of Test), OASIS (EMIX and Energy Interoperation), ISO/TC 205 Building Environment Design, and IEC PC 118 Smart Grid User Interface.

The division has an excellent publication record, including 63 peer-reviewed journal articles, 46 conference papers, and 45 NIST publications since 2010.

The division has developed widely used specialty software, including CONTAM contaminant transport in buildings (accessed through the NIST Internet site more than 4,000 times); the Climate Suitability Tool for natural ventilation; LoopDA, for natural ventilation design (accessed through the NIST Internet site more than 1,400 times); EVAP-COND, for the design of heat exchangers (accessed through the NIST Internet site more than 1,200 times per year); the APAR air handling unit performance assessment tool; the APAR-DD dual duct air handling unit performance assessment tool; the VPACC variable air volume performance assessment control chart; the TPACC terminal unit performance assessment control chart; the FDD-EA fault diagnostics and detection expert assistant; and the HVAC-CX heating, ventilating, air conditioning commissioning software tool. The Applied Economics Office (AEO) worked with the EED to develop the Building for Environmental and Economic Sustainability (BEES) assessment of sustainable building materials, which has more than 24,000 users in over 80 countries and is accessed through the NIST Internet site more than 5,000 times per month, and the BIRDS tool for assessment of sustainable buildings.

Opportunities and Challenges

The current output dissemination methods are well suited to the HVAC&R and commercial building sector, but they may not be as effective when the research area broadens to include the residential sector. New methods need to be developed, including more systematic dissemination to targeted audiences such as HVAC&R industry technical leaders (more frequent updates relating to refrigerant and vapor compression system advances are needed); the architectural and design community; home energy raters and energy auditors, who have an ascending influence in the construction industry; and university students, by creating, for example, data sets for virtual laboratories.

The division has significant impact through standards, publications, and software distribution, but informal dissemination methods and use of social media still need to be improved to affect a wider audience.

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